A layer construction for micro-mechanical manufacture of capacitive acceleration sensors, specifically for manufacturing a plurality of sensors simultaneously, can be produced with a minimum of favorably reproducible process steps. For example, the resiliently movable masses, required for the operation sensing acceleration, are cut free from a p-type or from an n-type doped silicon disk. Recesses for the electrical insulation of conductor paths and for freeing the connection contacts are arranged on this silicon disk in a manner known per se by the multiple application of photolithographic structure techniques and anisotropic etching. The masses of the flexural resonators, which are formed in this manner, are compulsorily constructed in a plate-shaped manner and, as a result of the conductivity of the doped silicon disk, act as movable capacitor electrodes without the need for additional steps. The associated counter-electrodes, together with suitable conductor paths, are vapor-deposited on Pyrex glass disks or are structured out of metallized Pyrex glass surfaces by photolithographic techniques. The glass-silicon-glass layer package is then connected by anodic bonding.
This advantageous construction, for the production of the layer package, has a considerable disadvantage when separating the acceleration sensors. This is due to the fact that this construction, which is as simple as possible, dispenses with an evacuation of the spaces in which the flexural resonators are constructed and because the conductor paths, connecting the counter-electrodes with external connection contacts, are guided out through suitable cut out portions in the silicon disk, as for example, when the separated sensors are not hermetically sealed. On the other hand, the separation must also be carried out in conformity with the process, such as by numerically controlled diamond cutting disks. This entails the risk that the coolant or lubricant, and particularly dust, will enter the relatively narrow gaps, in the range of hundredths of millimeters, between the movable masses of the flexural resonators and the counter-electrodes and will either mechanically block the flexural resonators or cause short circuits.
Accordingly, there arises the problem of preventing the penetration of dirt, as described above, while carrying out the desired separation of the acceleration sensors, in conformity with the process, and that of freeing and making accessible the connection contacts in an exactly defined and reproducible manner and with the simplest possible sensor architecture, when carrying out the separation.